Exocaster - I'd like to hear that JMP as well. Is the JMP considered more of a heavy blues and rock amp able to achieve tones like ac/dc to Rush or is it also like the JCM 800 which I guess is capable of Iron Maiden to late '80's thrash/early '90's death metal tone?
The JMP in question is a master volume 2204. Minus some minor circuit difference (caps, I think) it's the same amp as the JCM 800 2204 (only in a cooler looking headshell

).
On it's own, it'll do Iron Maiden and that sort of thing just fine. It needs a boost to go into heavier territory, but it's got a ballsy, agressive tone that more than makes up for any lack of gain. The single channel JMPs and JCM 800s- 2203s and 2204s- aren't really high gain amps on their own; they need a bit of a push (or a shove!

) from a pedal for thrash and death metal tones, but they'll certainly do 'em. The 2205 and 2210 two channel models have significantly more gain. They're retardedly loud, too. My 2204 cut just fine in a band mix with the master on 2, and it's a 50 watter. Old Marshalls seriously pwn modern high gainers volume-wise. As a frame of reference, I used to run a JCM 2000 TSL on 6 with the same band.
Here's a clip of the JMP. Heavy rock stuff in C# tuning, not metal, really. As far as the chain, It's an LTD EC1000 with a Duncan Custom 5 in the bridge --> Boss SD-1 with the level cranked up, gain somewhere under 9:00 --> JMP --> Marshall cab with Vintage 30s --> off-axis SM57. It's a bit fizzy, as the volume's really, really low- as in "1 or less", but it's the only clip I can find ATM. The rhythm guitars are all JMP; I played the lead through the SD-1 into a Pod XT with the Treadplate model.
JMP 2204 clip